Electrical switch with removable driving means

ABSTRACT

An electrical switch has a housing, and means is provided in the housing for access thereinto. Means is movable in the housing for completing a circuit therethrough, and means for actuating the circuit completing means is shiftable between at least two positions in the housing. Means is engaged with the actuating means in one position thereof for closing the access means, and means removable from the housing is insertable through the access means to conjointly drive the closing means from the access means and shift the actuating means to its other position to actuate the circuit completing means.

United States Patent [191 Walley [451 Dec. 31, 1974 ELECTRICAL SWITCHWITH REMOVABLE DRIVING MEANS [75] Inventor: Joseph M. Walley, Morrison,Ill.

[73] Assignee: General Electric Company, Fort Wayne, Ind. [22] Filed:Feb. 22, 1974 [21] Appl. No.: 444,884

[52] US. Cl. 200/153 LA, 200/42 R, 200/5 EB [51] Int. Cl. H0lh 9/24,I-IOlh 27/00 [58] Field of Search 200/42 R, 5 EB, 153 LA,

[56] References Cited UNITED STATES PATENTS 2,947,825 8/1960 Woodward200/5 EB 3,183,315 5/1965 Kiely 200/5 EB 3,600,529 8/l971 Gartland, .lr200/5 EB 3,714,383 1/1973 Leonard et al. 200/44 Primary Examiner-RobertK. Schaefer Assistant Examiner-William J. Smith [57] ABSTRACT Anelectrical switch has a housing, and means is provided in the housingfor access thereinto. Means is movable in the housing for completing acircuit therethrough, and means for actuating the circuit completingmeans is shiftable between at least two positions in the housing. Meansis engaged with the actuating means in one position thereof for closingthe access means, and means removable from the housing is insertablethrough the access means to conjointly drive the closing means from theaccess means and shift the actuating means to its other position toactuate the circuit completing means.

16 Claims, 10 Drawing Figures ELECTRICAL SWITCH WITH REMOVABLE DRIVINGMEANS BACKGROUND OF THE INVENTION This invention relates in general toelectrical switches for use with appliances or the like and inparticular to such electrical switches operated by means removabletherefrom for preventing unauthorized operation.

In the past, various electrical switches have been operated by aremovable key which was selectively inserted through an opening in theelectrical switch housing to effect actuation of the electrical switchcomponent parts for making or breaking an electrical circuit. In some ofthe past electrical switches, a removable key was selectively insertablethrough a plurality of openings in the electrical switch housing foreffecting actuating of the electrical switch component parts to make orbreak a plurality of electrical circuits. Some of the key receivingopenings provided in the past key operated electrical switches wereprovided with particular or peculiar shapes in an attempt to prevent theentry of unauthorized keys or foreign tools, such as screwdrivers,nails, hairpins, knife blades, pencils, etc. One of the disadvantageousfeatures of this type of past electrical switch was that irrespective ofthe particular shape of the key receiving opening utilized, someunauthorized key or foreign tool undoubtedly could be insertedthereinto. In other past electrical switches, the key receiving openingwas restricted, i.e. made very narrow or slot-like, in an attempt toprevent the insertion of unauthorized keys or foreign tools; however,generally the same disadvantageous feature was applicable to such narrowkey receiving openings as discussed above with respect to those havingpeculiar shapes. Of course, other disadvantageous features with respectto electrical safety and deformation of component parts of the pastelectrical switches are ancillary to the aforementioned disadvantageousfeature with respect to the insertion of unauthorized keys or foreigntools into the past key operated type electrical switches.

SUMMARY OF THE INVENTION Among the several objects of the presentinvention may be noted the provision of an electrical switch adapted tobe operated by means removable therefrom which overcomes thedisadvantageous or undesirable features discussed hereinbefore, as wellas others, with respect to the prior art electrical switches; theprovision of such electrical switch which is positively blocked againstthe entry of unauthorized means for the operation thereof; the provisionof such electrical switch having means internally thereof for blockingthe entry of unauthorized keys or foreign tools or the like; theprovision of such electrical switch in which the blocking means iseffective to actuate other components of the electrical switch; theprovision of such electrical switch in which the blocking means isdisplaced upon the insertion of an authorized means for operating theelectrical switch and automatically returned to its blocking positionupon removal of the authorized means for operating the electricalswitch; the provision of such electrical switch which may be selectivelymomentarily actuated; and the provision of such electrical switch whichis simplistic in design, economically manufactured, and easilyassembled. Other objects and advantageous features will in part beapparent and in part pointed out hereinafter.

In general, an electrical switch in one form of the invention has ahousing and means in the housing for access into an interior portionthereof. Means is movable in the housing for completing a circuittherethrough, and means for actuating the circuit completing means isshiftable between at least two positions in the housing. Means isengaged with the actuating means for generally closing the access meanswith the actuating means is in one position thereof, and means removablefrom the housing is insertable through the access means for driving theclosing means to conjointly displace it away from the access means anddrivingly shift the actuating means to its other position to actuate thecircuit completing means.

Also in general, the electrical switch in one form of the invention mayalso additionally include means for momentarily operating the circuitcompleting means, and the operating means is adapted to both drive theclosing means and be driven by it. The operating means is driven by theclosing means, in response to the driving thereof by the driving means,toward an operative position in the housing effecting actuation of thecircuit completing means, and resilient means returns the operatingmeans from its operative position toward an original position in thehousing to effect de-actuation of the circuit completing means upon theremoval of the driving means from the housing. The operating meansdrives the closing means to its position for closing the access meansupon the return of the operating means to its original position.

Further in general and in one form of the invention, an electricalswitch has a housing with a contact therein, and a contact blade ismovably supported in the housing for making and breaking engagement withthe contact. A slider is shiftable in the housing relative to thecontact blade, and a pair of opposite edges are provided on the slider.A cam surface in one of the opposite edges drives the contact blade toeffect the making and breaking engagement thereof with the contact whenthe slider is in the one position and the other position thereof,respectively, and a pair of inclined surfaces are provided in the otherof the opposite edges. A generally stationary plate is disposed in thehousing adjacent the slide and includes an edge portion having a pair ofguide slots therein for transverse alignment, at least a part, with theinclined surfaces, respectively. A pair of openings in the housing aregenerally vertically aligned with the guide slots, and a push buttonactuator is generally reciprocably movable in the housing extendingthrough one of the openings. Extension means on the push button actuatorengages with the housing to prevent displacement therefrom of the pushbutton actuator and extends between the slider and plate for guidingengagement in one of the guide slots and both driving and drivenengagement with one of the inclined surfaces. The push button actuatoris movable in response to an applied force thereon to move the extensionmeans within the one guide slot and drive the one inclined surface toshift the slider from its one position to the other position thereof. Arod extends between the slider and the plate for guiding engagement inthe other of the guide slots and both driving and driven engagement withthe other of the inclined surfaces, and the rod is driven by the otherinclined surface generally upwardly in the other guide slot toward aposition in seating engagement with the housing generally about theother of the openings to block it when the slider is shifted to itsother position. A key, which is removable from the housing, has a shankwith a configuration closely conforming to that of the other opening forselective insertion therethrough into driving engagement with the rod,and the rod is driven, upon the driving engagement of the shanktherewith, generally downwardly in the other guide slot away from itsblocking position thereby to drive the other inclined surface and effectreturn shifting of the slider from its other position to the oneposition thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2;

FIGS. 4, 5 and 6 are plan views of the stationary plate and sliders ofthe electrical switch of FIG. 1;

FIG. 7 is a side elevational view of a key for operating the electricalswitch of FIG. 1;

FIG. 8 is a side elevational view of an alternative key for operatingthe electrical switch of FIG. 1;

FIG. 9 is a plan view of a cover which may be employed with theelectrical switch of FIG. 1 which is also embodied in one form of thepresent invention; and

FIG. 10 is a bottom elevational view of the cover of FIG. 9.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

The following examples illustrate the invention and are not to beconstrued as limiting in any manner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsin general, there is shown at 1 an electrical switch having a housing 3,and means, such as at least an opening 5, is provided in the housing foraccess into an interior portion, such as a chamber 7, thereof (FIGS. 1and 2). Means, such as a contact or switch blade 9 or the like, ismovable in housing 3 for completing a circuit (not shown) therethrough,and means, such as an elongate slider 11, for actuating the switch bladeis shiftable between at least two positions in the housing. Means, suchas a rod 13 or the like, is engaged with slider 11 for generally closingopenings 5 when the slider is in one position thereof, and means, suchas a key 15 or the like (FIG. 7), which is removable from housing 3, isselectively insertable through the opening for driving the rod toconjointly displace it away from the opening and drivingly shift theslider to its other position to actuate the switch blade.

More particularly with reference to FIGS. 1 and 2, housing 3, which isformed from a dielectric material as well known in the art, is providedwith a base wall 17 within chamber 7, and opening 5 extends generallyvertically through the housing intersecting with the base wall. Anotheropening 19, in which a push button actuator, such as an off-key 21, isreciprocally movable, as discussed hereinafter, also extends generallyvertically through housing 3 intersecting with base wall l7, and arecess 23, in which is disposed a spring loaded detent 25, as discussedhereinafter, is provided in chamber 7 intersecting with the base wallbetween openings 5, 19. A closure member or cover 27, which is alsoformed from a dielectric material, is removably secured to housing 3 bysuitable means, such as a plurality of screws (not shown), and terminalpairs 29, 31 and 33, 35 are molded or otherwise fixedly disposed in thehousing for connection in the electrical circuit (not shown).

As shown in FIGS. 2 and 3, contact blade 9 and another switch or contactblade 37 are pivotally movable and supported in housing 3 in electricalconnection with terminals 29, 31 in a manner well known to the art, andthe switch blades are formed from a resilient, current conductive metalor metal alloy. Switch blade 37 along with switch blade 9 may alsoconstitute the aforementioned circuit completing means. Contacts 39, 41are disposed on switch blades 9, 37 for making and breaking engagementwith a pair of mating or stationary contacts (not shown) carried on apair of generally stationary busses 43, 45 or the like therefor withinhousing chamber 9 which are electrically connected with terminals 31,35, respectively.

Guiding means, such as an elongate stationary plate 47, is disposed inhousing chamber 7 and interposed generally in side-by-side guidingrelation between slider 11 and means, such as another elongate slider49, for momentarily operating the circuit completing means, as discussedhereinafter, and the plate and sliders are also shown in FIGS. 46.Engagement of sliders ll, 47 with the side walls of housing chamber 7predeterminately limits transverse displacement of the sliders from thegeneral side-by-side guiding relation with plate 47. Plate 47 has upperand lower edges 51, 53, and a pair of generally vertical orperpendicularly extending guide slots 55, 57 are provided through theupper edge. Guide slots 55, 57 are positioned generally in verticalalignment with openings 5, 39 of housing 3. Upper edge 51 of plate 47has a notch 59 therein in which is received spring loaded detent 25disposed in housing recess 23 thereby to maintain the plate generallystationary or against generally longitudinal or end-wise sliding orshifting movement with sliders ll, 49, as discussed hereinafter. A pairof spaced tabs 61 are integrally formed on plate 47 depending from loweredge 53 thereof in abutment with cover 27 wherein the lower edgegenerally transversely spans the switch blades 9,

Slider 11 has upper and lower edges 63, 65 in which a pair of oppositelydisposed inclined surfaces 67, 69 are provided, and the inclinedsurfaces are generally, at least in part, transversely aligned withguide slots 55, 57 of plate 47 for overlaying or overlapping relationtherewith upon shifting movement of the slider in housing chamber 7, asdiscussed hereinafter. A camming surface or portion 71 is provided onlower edge 65 of slider 11 for actuating engagement with switch blade 9,and a pair of spaced tabs 73 are also integrally formed in slider 11depending from the lower edge thereof in sliding or shifting engagementwith cover 27 for movement generally in the longitudinal or left-rightend-wise direction (as seen in FIGS. 2 and 3). Tabs 73 space lower edge65 from cover 27 so that the lower edge spans switch blades 11, 37.

Slider 49 has upper and lower edges 75, 77, and an inclined surface 79is provided on the upper edge generally in a transverse alignment, atleast in part, with guide slot 55 of plate 47 and inclined surface 69 ofslider 11 for overlaying or overlapping relation therewith upon theshifting or sliding movement of slider 49 in housing chamber 7, asdiscussed hereinafter. Slot 81 is also provided in slider 49 throughupper edge 75 thereof generally spanning the overlaying or overlappingrelation of guide slot 57 in plate 47 and inclined surface 67 ofsliderll. Another camming surface or portion 83 is provided on loweredge 77 of slider 49 for momentary actuating engagement with switchblade 37, and a pair of spaced tabs 85 are also integrally formed on theslider depending from the lower edge thereof in sliding or shiftingengagement with cover 27 for movement generally in the longitudinal orleft-right end-wise direction(as seen in FIGS; 2 and 3). Tabs 83 spacelower edge 77 from cover 27 so that the lower edge spans switch blades11, 37. A retaining notch is provided in the slider at 87 forretainengagement with resilient means, such as a spring 89, which isbiased between slider 49 and housing 3 within housing chamber 7 urgingthe slider rightwardly (as seen in FIG. 2) at all times.

Referring with particularity again to FIGS. 2 and 3, off-key 21, whichis shown in its in or off position, has ashank orshaft 91 reciprocallymovable through housing opening 19, and a generally transverselyextending rod 93 is fixedly connected by suitable means (not shown) tothe interior end of the shaft. Rod 93 is engagable with base wall 17 ofhousing chamber 7 generally about opening 19 to prevent displacement ofoffkey 21 from housing 3, and the rod is also guidably and slidablyreceived in guide slot 57 of plate 47 and disposed for both driving anddriven engagement with inclined surface 67 of slider 11. Closing meansor rod 13 extends transversely of plate 47 and sliders 11, 49, and therod is generally floatably movable in guide slot 55 of the plate insliding and guiding engagement therewith and disposed for both drivingand driven engagement with inclined surfaces 69, 79 of sliders 11, 49,respectively. A seat, indicated at 95, is provided on base wall 17 ofhousing chamber 7 generally about opening 13 therein, and as seen inFIG. 2, rod 13 is urged by both inclined surfaces 69, 79 of sliders 11,49 generally upwardly in guide slot 55 of plate 47 toward engagementwith seat 95 thereby to block housing opening 5.

Removable key 15, FIGS. 7 and 8, is provided with a generally flat shank97 having a pair of opposite prongs or tines 99, and the configurationsof the tines closely conform to those of housing openings 5 throughwhich the tines may be manually inserted for driving engagement with rod13 to effect actuation of electrical switch 1, as described hereinafter.It is understood that other shapes for housing opening 5 and key may beutilized within the scope of the invention.

OPERATION In the operation of electrical switch 1, it will be recalledthat sliders ll, 49 are shiftable or translatable in housing chamber 7relative to stationary plate 47 in a generally left-right or end-wisedirection (as seen in FIG. 2). When slider 11 is in its one or leftwardtranslated position, camming surface 71 thereof is engaged with switchblade 9 depressing it toward cover 27to disengage contact 39 from buss43 and interrupt the circuit through housing 3 between terminals 29, 31.The compressive forceof spring 89 urges slider 49 toward its oneor'rightward translated position (as seen in FIG. 2), and with slider 49so urged to its rightward translated position, camming surface 83 isengaged with switch blade 37 depressing it toward cover 27 to disengagecontact 41 from buss 45 and interrupt the circuit through housing 3between terminals 33, 35. In the following discussion with respect tofunction of the various components of electrical switch 1, the operationof slider 11 will be considered separately prior to that of slider 49for the sake of clarity albeit understood that sliders 11, 49 may be insome instances simulta neously operable.

To initiate the operation of electrical switch 1, an authorized operatorinitially inserts tines 99 of removable key 15 through generally matinghousing opening 5 therefor to drivingly engage the free ends of thetines with rod 13 which is urged by sliders 11, 49 toward its blockingposition with respect to the opening in engagement with seat 95.Thereafter, a manual force applied by the operator onto key 15 drivesrod 13 generally vertically downwardly (as seen in FIG. 2) within guideslot 55 of plate 47 so as to displace the rod away from its seat and itsblocking position with respect to housing opening 5. When slider 11 isin its one or leftward translated position interrupting the circuitthrough housing 3 between terminals 29, 31, as previously mentioned,inclined surfaces 67, 69 of the slider are disposed, at least in part,in transverse overlaying relation with respect to guide slots 55, 57 ofplate 47; therefore, the applied force downward movement of rod 13 inguide slot 55 causes the rod to drive on inclined surface 69. Thisdriving engagement between rod 13 and inclined surface 69 translates orshiftably moves or slides slider 11 from its original or leftwardtranslated position in the righward direction (as seen in FIG. 2) towardits other opposite or rightward translated or actuating position toeffect actuation of switch blade 9. This rightward translatory movementof slider 11 toward its other or rightward translated position inhousing 3 disengages camming surface 71 from switch blade 9, and theinherent resiliency of the switch blade moves it upwardly toward acircuit making position engaging contact 39 with buss 43 and completingthe circuit through the housing between terminals 29, 31. It may benoted that rod 13 is not only utilized to block opening 5when'electrical switch 1 is de-energized or de-actuated but is alsoresponsive to the operator applied force exerted thereon by key 15 toeffect actuation of slider 11 for completing the circuit through thehousing. The positive or predetermined blocking effect of rod 13 withrespect to housing opening 13 prevents the entry of foreign tools of thetype previously mentioned thereby to obviate deformation of componentparts of electrical switch 1 and the possibility of such foreign toolscontacting an electrically hot part of the electrical switch. Aspreviously mentioned, in the in" or off position of push button actuator21 (as seen in FIG. 2), rod 93 thereof and inclined surface 67 of slider11 are engaged; therefore, the rightward translatory movement of theslider causes inclined surface 67 to drive on rod 93. This drivingengagement between inclined surface 67 and rod 93 drives or moves therod generally vertically upwardly in guide slot 57 of plate 47, and pushbutton actuator 21 is, of course, displaced along with its rod to the*out" or inoperative position thereof. When slider 11 in its rightwardtranslated position completing the circuit through housing 3, as abovedescribed, key 15 may be removed from the housing for sake keeping, ifdesired.

When it is desired to de-actuate or de-energize electrical switch 1, theoperator applies a manual force onto push button actuator 21 moving itfrom its out position toward the in position thereof. This applied forcemovement of push button actuator 21 conjointly drives rod 93 generallyvertically downwardly (as seen in H6. 2) within guide slot 57 of platecausing the rod to drive on inclined surface 67 of slider l 1. Thisdriving engagement between rod 93 and inclined surface 67 translates orshiftably moves slider 11 from its rightward translated position in theleftwardly direction back toward its original or leftwardly translatedposition to effect de-actuation of switch blade 9. This leftward orreturn translatory of slider 11 toward its original leftward position inhousing 3 re-engages camming surface 71 with switch blade 9 to depressit toward its breaking position disengaging contact 39 from buss 43 andagain interrupting the circuit through the housing between terminals 29,31. Since rod 13 and inclined surface 69 of slider 11 are engaged, aspreviously mentioned, the leftward translatory movement of the slidercauses inclined surface 69 to drive on rod 13. This driving engagementbetween inclined surface 69 and rod 13 drives or moves the rod generallyvertically upwardly in guide slot 55 of plate 47 returning the rod toits blocking position in engagement with seat 95. It may be noted thatupon de-actuation of electrical switch 1, as described above, rod 13 isautomatically returned to its blocking position with respect to housingopening 5. Such automatic return movement of rod 13 will drive key 15to, at least in part, effect ejection thereof from opening if the key isin the opening.

Turning now to the function of the momentarily operating slider 49, itwill be recalled that this operating aspect of electrical switch 1 isseparately discussed only for the purpose of clarity, and it isunderstood that if momentary energization of the electrical switch isnot desired, slider 49 and its associated component parts for completingthe circuit through housing 3 between terminals 33, 35 may be omittedfrom electrical switch 1. A typical application for an electrical switchin which momentary energization is desirable is for starting an electricmotor (not shown). In this electric motor application, it may bedesirable to effect the closure of a pair of contacts, such as contacts39, 41 for instance, in order to accommodate the initial in-rush ofcurrent which occurs when the motor is initially energized; however,thereafter it may be desirable to maintain only one contact, such ascontact 39 for instance, closed during the normal running of the motorafter the starting thereof.

When slider 11 is in its original or leftward position, the appliedforce movement of rod 13 by key downwardly in guide slot 55 of plate 47not only effects the rightward translation of slider 11 to its rightwardtranslated position to complete the circuit through housing 3 betweenterminals 29, 31, as previously described, but also effects thesimultaneous actuation of momentarily actuated slider 49. Since thecompressive force of spring 89 normally biases slider 49 toward anoriginal or rightward position in housing 3 engaging inclined surface 79of the slider with rod 13, the applied force movement of the roddownwardly in plate guide slot 55 causes'the rod to drive on inclinedsurface 79. This driving engagement between rod 13 and inclined surface79 translates or shiftably moves or slides slider 49 from its originalposition in housing 3 in the leftward direction (as seen in FIG. 2)against the compressive force of spring 89 toward a leftward translatedor actuating position to effect actuation of switch blade 37 generallysimultaneously with the actuation of switch blade 9 by the rightwardtranslatory movement of slider 11, as previously described. Thisleftward translatory movement of slider 49 toward its leftwardtranslated positions in housing 3 disengages camming surface 83 fromswitch blade 37, and the inherent resiliency of the switch blade movesit upwardly toward a making position engaging contact 41 thereof withbuss 45 and completing the circuit through the housing between temrinals33, 35 generally at the same time the circuit is also completed betweenterminals 29, 31, as previously described.

Thus, with the applied force being exerted through key 15 onto rod 13,sliders ll, 49 are oppositely displaced or translated to theirrespective rightward and leftward translated positions. However, whenthe open ator removes key 15 from housing 3 through opening 5 thereby toeliminate the applied force, slider 11 remains in its rightwardtranslated position maintaining the circuit through the housingcompleted between terminals 29, 31, but the compressive force of spring89 is effective to return slider 49 rightwardly in the housing towardits original position. This return translatory movement of slider 49re-engages camming surface 83 thereof with switch blade 37 depressing ittoward cover 27 and moving contact 41 to its breaking positiondisengaged from buss 45 and interrupting the circuit through housing 3between terminals 33, 35. It may be noted that the circuit throughhousing 3 between terminals 29, 31 made by slider 11 in its rightwardtranslated position remains completed and the circuit which was madebetween terminals 33, 35 by the momentary actuation of slider 49 isinterrupted. Since inclined surface 79 of slider 49 is drivingly engagedwith rod 13, the compressive force of spring 89 causes inclined sur face79 to drive on the rod during the return movement of the slider to itsoriginal rightward translated position. This driving engagement betweeninclined surface 79 and rod 13 drives or moves the rod generallytypically upwardly in guide slot 55 of plate 47 returning the rod to itsblocking position with respect to housing opening 5 in engagement withseat 95. It may be noted that the momentary actuation of slider 49automatically returns rod 13 to its blocking position with respect tohousing opening 3 when slider 11 is in its rightwardly translatedposition maintaining the circuit through the housing completed betweenterminals 29, 31.

Referring now to FIG. 8, resilient means, such as spring 101, may bedisposed about chank 97 of key 15, and upon insertion of the key intohousing opening 5 to effect actuation of electrical switch 1, the springis compressed between the key and housing 3. The compressive force ofspring 101 will effect automatic ejection of key 15 from housing opening5 when the applied force is removed from the key by the operator, aspreviously mentioned.

In FIGS. 9 and 10, there is shown in general means, such as a rotatablemember 103, adapted to be disposed on housing 3 exteriorly thereof fornormally blocking opening 5 and adapted to be rotatably displaced, andmeans, such as passage 105 generally complimentary to housing opening 5,in the blocking means for alignment with the housing. opening to permitthe passage of key 15 therethrough into the housing opening when theblocking means is selectively displaced.

More particularly, a cover plate l07 is adapted to be mounted to orsuperposed over the face of housing 3 (as seen in FIG. 1) of electricalswitch 1 by suitable means, such as a plurality of screws or the like(not shown). Cover platel07 is slotted at 109 to accommodate shank 91 ofpush button actuator 21 which extends therethrough, and a hole oraperture 111 is provided through the cover plate for dispositiongenerally about opening in housing 3. Rotatable member 103 is positionedover aperture 111 on the underside of cover plate 107, as illustrated inFIG. 10, and is rotatably retained thereon by a plurality of integrallyformed tabs 113 lanced from the cover plate in a manner well known tothe art. A projection or finger 115 is provided on rotatablemember 103,and a spring 117 is biased between the finger and cover plate 107 so asto normally rotatably misalign complimentary passage 105 in therotatable member from housing opening 5.

In order to insert key into housing opening 5 to effect actuation ofelectrical switch 1 when cover plate 107 is mounted thereto, tines 99are inserted into passage 105 of rotatable member 103, and the key androtatable member are conjointly rotated against the relatively lightcompressive force of spring 115 to a position aligning the passage withthe housing opening. When housing opening 5 and passage 105 of rotatablemember 103 are thus aligned, key 15 may be moved therethrough to effectactuation of electrical switch 1, as previously described. When key 15is removed from housing opening 5 and rotatable member passage 105, thecompressive force of spring 115 rotatably returns rotatable member 103to its original position again effecting the misalignment betweenhousing opening 5 and rotatable member passage 105. It may be noted thatthe predetermined positive misalignment of rotatable member passage 105with housing opening 5 provides an additional safety feature to preventinsertion of foreign tools or the like directly into the housingopening.

From the foregoing, it is now apparent than an electrical switch 1 hasbeen provided meeting the objects and advantageous features therefor setout hereinbefore, as well as others, and that changes may be made withrespect to the precise arrangements, shapes and details of theconstructions set forth herein for purposes of illustration by thoseskilled in the art without departing from the spirit or the scope of theinvention which is set out by the claims which follow.

What I claim as new and desire to secure by Letters Patent in the UnitedStates is:

1. An electrical switch comprising a housing, means in the housing foraccess into an interior portion thereof, means movable in the housingfor completing a circuit therethrough, means for actuating the circuitcompleting means and shiftable between at least two positions in thehousing, means engaged with the actuating means for generally closingthe access means when the actuating means is in one position thereofeffecting de-actuation of the circuit completing means, and meansremovable from the housing and selectively insertable through the accessmeans for driving the closing means to conjointly displace it away fromthe access means and drivingly shift the actuating means to its otherposition to actuate the circuit completing means.

2. An electrical switch as set forth in claim 1, wherein the closingmeans comprisesmeans for seating engagement with the interior portion ofthe housing generally about the access means therein.

3. An electrical switch as set forth in claim 1, wherein the closingmeans comprises means for driving engagement with the actuating means todrivingly shift it to its other position when the closing means isdriven by the driving means.

4. An electrical switch as set forth in claim 1, wherein the closingmeans comprises means for seating engagement with the housing generallyabout the access means therein and driving engagement with the actuatingmeans in the one position thereof.

5. An electrical switch as set forth in claim 1, wherein the drivingmeans is constituted by a key having a shank portion with aconfiguration conforming closely with that of the access means.

6. An electrical switch as set forth in claim 1, further comprisingmeans movable through at least a portion of the housing and operablegenerally in response to a manually applied force thereon for shiftingthe actuating means from its other position to the one position thereofto de-actuate the circuit completing means.

7. An electrical switch as set forth in claim 6, wherein the shiftingmeans includes means for engagement with the interior portion of thehousing to prevent displacement therefrom of the shifting means.

8. An electrical switch as set forth in claim 6, wherein the actuatingmeans includes means engaged with the closing means for driving it to aposition in seating en gagement with at least a part of the interiorportion of the housing about the access means when the actuating meansis shifted to its one position.

9. An electrical switch as set forth in claim 1, further comprisingmeans adapted to be engaged between the driving means and the housingexteriorly thereof for returning the driving means upon the insertionthereof through the access means.

10. An electrical switch as set forth in claim 1, further comprisingmeans engaged with both the closing means and the actuating means forguiding the displacement and shifting movements thereof, respectively.

lll. An electrical switch as set forth in claim 10, further comprisingmeans in the housing for engagement with at least a part of the guidingmeans to maintain it generally stationary in the housing.

12. An electrical switch as set forth in claim 1, further comprisingmeans engaged with the closing means and driven generally conjointlytherewith by the driving means for momentarily operating the circuitcompleting means when the actuating means is in its other position.

13. An electrical switch as set forth in claim 12, wherein themomentarily operating means includes resilient means forconjointlyreturning the momentarily operating means and closing meanswhen the driving means is removed from the housing.

14. An electrical switch as set forth in claim 1, further comprisingmeans for momentarily operating the circuit completing means and adaptedto both drive the closing means and be driven by it, the operating meansbeing driven by the closing means in response to the driving thereof bythe driving means toward an operative position in the housing effectingactuation of the circuit completing means, and resilient means forreturning the operating means from its operative position toward anoriginal position in the housing to effect deactuation of the circuitcompleting means upon the removal of the driving means from the housing,the operating means driving the closing means to its position forclosing the access means upon the return of the operating means to itsoriginal position.

15. An electrical switch as set forth in claim 1, further comprisingmeans disposed on the housing exteriorly thereof for normally blockingthe access means and adapted to be selectively displaced, and means inthe blocking means for alignment with the access means to permit passageof the driving means therethrough into the access means when theblocking means is selectively displaced.

16. In an electrical switch having a housing, a contact within thehousing, a contact blade movably supported in the housing for making andbreaking engagement with the contact, a slider shiftable in the housingrelative to the contact blade at least between two positions, a pair ofopposite edges on the slider, a cam surface on one of the opposite edgesfor driving the contact blade to effect the making and breakingengagement thereof with the contact when the slider is in its oneposition and the other position-thereof, respectively, a pair ofinclined surfaces in the other of the opposite edges, a generallystationary plate disposed in the housing adjacent the slider includingan edge portion having a pair of guide slots therein for transversealignment with at least a part of the inclined surfaces, respectively, apair of openings in the housing and generally vertically aligned withthe guide slots, a push button actuator generally reciprocally movablein the housing and extending through one of the openings, extensionmeans on the push button actuator for engagement with the housing toprevent displacement therefrom of the push button actuator and extendingbetween the slider and plate for guiding engagement in one of the guideslots and both driving and driven engagement with one of the inclinedsurfaces, the push button actuator being movable in response to anapplied force thereon to move the extension means within the one guideslot and drive the one inclined surface to shift the slider from its oneposition to the other position thereof; a rod extending between theslider and plate for guiding engagement in the other of the guide slotsand both driving and driven engagement with the other of the inclinedsurfaces, the rod being driven by the other inclined surface generallyupwardly in the other guide slot toward a position in seating engagementwith the housing generally about the other of the openings to block itwhen the slider is shifted to its other position, and a key removablefrom the housing and having a shank with a configuration closelyconforming to that of the other opening for selective insertiontherethrough into driving engagement with the rod, the rod being drivenupon the driving engagement of the shank therewith generally downwardlyin the other guide slot away from its blocking position thereby to drivethe other inclined surface and effect return shifting of the slider fromits other position to the one position thereof.

1. An electrical switch comprising a housing, means in the housing foraccess into an interior portion thereof, means movable in the housingfor completing a circuit therethrough, means for actuating the circuitcompleting means and shiftable between at least two positions in thehousing, means engaged with the actuating means for generally closingthe access means when the actuating means is in one position thereofeffecting deactuation of the circuit completing means, and meansremovable from the housing and selectively insertable through the accessmeans for driving the closing means to conjointly displace it away fromthe access means and drivingly shift the actuating means to its otherposition to actuate the circuit completing means.
 2. An electricalswitch as set forth in claim 1, wherein the closing means comprisesmeans for seating engagement with the interior portion of the housinggenerally about the access means therein.
 3. An electrical switch as setforth in claim 1, wherein the closing means comprises means for drivingengagement with the actuating means to drivingly shift it to its otherposition when the closing means is driven by the driving means.
 4. Anelectrical switch as set forth in claim 1, wherein the closing meanscomprises means for seating engagement with the housing generally aboutthe access means therein and driving engagement with the actuating meansin the one position thereof.
 5. An electrical switch as set forth inclaim 1, wherein the driving means is constituted by a key having ashank portion with a configuration conforming closely with that of theaccess means.
 6. An electrical switch as set forth in claim 1, furthercomprising means movable through at least a portion of the housing andoperable generally in response to a manually applied force thereon forshifting the actuating means from its other position to the one positionthereof to de-actuate the circuit completing means.
 7. An electricalswitch as set forth in claim 6, wherein the shifting means includesmeans for engagement with the interior portion of the housing to preventdisplacement therefrom of the shifting means.
 8. An electrical switch asset forth in claim 6, wherein the actuating means includes means engagedwith the closing means for driving it to a position in seatingengagement with at least a part of the interior portion of the housingabout the access means when the actuating means is shifted to its oneposition.
 9. An electrical switch as set forth in claim 1, furthercomprising means adapted to be engaged between the driving means and thehousing exteriorly thereof for returning the driving means upon theinsertion thereof through the access means.
 10. An electrical switch asset forth in claim 1, further comprising means engaged with both theclosing means and the actuating means for guiding the displacement andshifting movements thereof, respectively.
 11. An electrical switch asset forth in claim 10, further comprising means in the housing forengagement with at least a part of the guiding means to maintain itgenerally stationary in the housing.
 12. An electrical switch as setforth in claim 1, further comprising means engaged with the closingmeans and driven generally conjointly therewith by the driving means formomentarily operating the circuit completing means when the actuatingmeans is in its other position.
 13. An electrical switch as set forth inclaim 12, wherein the momentarily operating means includes resilientmeans for conjointly returning the momentarily operating means andclosing means when the driving means is removed from the housing.
 14. Anelectrical switch as set forth in claim 1, further comprising means formomentarily operating the circuit completing means and adapted to bothdrive the closing means and be driven by it, the operating means beingdriven by the closing means in response to the driving thereof by thedriving means toward an operative position in the housing effectingactuation of the circuit completing means, and resilient means forreturning the operating means from its operative position toward anoriginal position in the housing to effect de-actuation of the circuitcompleting means upon the removal of the driving means from the housing,the operating means driving the closing means to its position forclosing The access means upon the return of the operating means to itsoriginal position.
 15. An electrical switch as set forth in claim 1,further comprising means disposed on the housing exteriorly thereof fornormally blocking the access means and adapted to be selectivelydisplaced, and means in the blocking means for alignment with the accessmeans to permit passage of the driving means therethrough into theaccess means when the blocking means is selectively displaced.
 16. In anelectrical switch having a housing, a contact within the housing, acontact blade movably supported in the housing for making and breakingengagement with the contact, a slider shiftable in the housing relativeto the contact blade at least between two positions, a pair of oppositeedges on the slider, a cam surface on one of the opposite edges fordriving the contact blade to effect the making and breaking engagementthereof with the contact when the slider is in its one position and theother position thereof, respectively, a pair of inclined surfaces in theother of the opposite edges, a generally stationary plate disposed inthe housing adjacent the slider including an edge portion having a pairof guide slots therein for transverse alignment with at least a part ofthe inclined surfaces, respectively, a pair of openings in the housingand generally vertically aligned with the guide slots, a push buttonactuator generally reciprocally movable in the housing and extendingthrough one of the openings, extension means on the push button actuatorfor engagement with the housing to prevent displacement therefrom of thepush button actuator and extending between the slider and plate forguiding engagement in one of the guide slots and both driving and drivenengagement with one of the inclined surfaces, the push button actuatorbeing movable in response to an applied force thereon to move theextension means within the one guide slot and drive the one inclinedsurface to shift the slider from its one position to the other positionthereof; a rod extending between the slider and plate for guidingengagement in the other of the guide slots and both driving and drivenengagement with the other of the inclined surfaces, the rod being drivenby the other inclined surface generally upwardly in the other guide slottoward a position in seating engagement with the housing generally aboutthe other of the openings to block it when the slider is shifted to itsother position, and a key removable from the housing and having a shankwith a configuration closely conforming to that of the other opening forselective insertion therethrough into driving engagement with the rod,the rod being driven upon the driving engagement of the shank therewithgenerally downwardly in the other guide slot away from its blockingposition thereby to drive the other inclined surface and effect returnshifting of the slider from its other position to the one positionthereof.